Chris Christie among possible candidates to replace Jeff Sessions

Sacked US Attorney General Jeff Sessions, left, with his chief of staff, now acting attorney general, Matthew Whitaker. AFP

Donald Trump’s firing of his attorney general triggered Democratic fears of a “constitutional crisis” if the White House moves to impede the Russia probe, while the president himself was looking at list of candidates for the post.

The sacking of Jeff Sessions loomed large over the policy debate in Washington on Thursday, two days after the midterm elections that gave Democrats a majority in the House and will bring more oversight of the White House. In both camps, Republican and Democratic, there is a consensus that the dismissal was about the investigation by Special Counsel Robert Mueller investigation, and Mr Trump’s desire to have an attorney general who would protect him rather than recuse himself from the process, as Mr Sessions did last year without consulting with the White House.

The appointment of Matthew Whitaker, Mr Sessions' chief of staff, as acting attorney general rather that Assistant Attorney General Rod Rosenstein, appeared to be the first step toward that end.

Mr Whitaker has criticised the special counsel and said his investigation into Russia's role in the 2016 presidential election had gone too far. According to experts, he can choose to conceal the indictments and cut funding for Mr Mueller's probe. The president’s son, Donald Trump Jr, has reportedly told friends that he expects to be indicted. Roger Stone, a longtime adviser to Mr Trump, is another name that Mr Mueller is examining extensively for communications with WikiLeaks and the Russians during the 2016 campaign.

Ken Gude, a legal scholar at the Center for American Progress, told The National that the “only reason to force out Sessions, who has been delivering on Mr Trump’s agenda — and skipping the Department of Justice succession is to avoid Mr Rosenstein being Acting AG — is to obstruct the investigation”.

“Mr Whitaker is publicly on the record saying Bob Mueller has gone too far and urging Rosenstein to hamper the investigation,” Mr Gude told The National.

Paul Rosenzweig, a legal expert and a former deputy assistant secretary for policy at the Department of Homeland Security, agreed. He told The National that Mr Trump only fired his attorney general so that he could replace him with Mr Whitaker. He argued that while Mr Trump would not be inclined to take an explosive route and fire Bob Mueller, neither the House nor the Senate can currently protect the special counsel if that were to happen. There is a bill in the Senate to prevent such an action, but the Republican leadership has not called for a vote on its passage.

Meanwhile, the White House has already started looking at replacements for Mr Sessions.

CBS reported on Thursday that the former New Jersey governor Chris Christie, a friend of Mr Trump, is one of the names being considered. NBC reported that Mr Christie was at the White House for meetings on Thursday. While Mr Christie was an attorney for the district of New Jersey for six years and is known for his loyal defence of Mr Trump, his own history in the Trump campaign and possible knowledge about contacts with Russia have raised questions about whether he would also recuse himself if he were he to be nominated.

Kris Kobach, a conservative figure who lost on Tuesday in his bid to become governor of Kansas, is another name on the list. His campaign manager, J R Claeys, told Politico it was "definitely a possibility”. Mr Kobach is a staunch supporter of Mr Trump and would carry out a conservative agenda at the Department of Justice, unlike Mr Christie who is viewed more of a moderate Republican.

Other names floated for the position were Bill Barr, attorney general under President George H Bush. Senator Lindsey Graham, a new ally of Mr Trump in the Senate, is another name on the shortlist. But when asked by NBC if he wanted the position, Mr Graham said “no, no, no”, and that he was expecting a replacement to be confirmed by the new Senate next year.

Another loyal friend of Mr Trump, Florida attorney general Pam Bondi, is also being discussed as a candidate.The Wall Street Journal mentioned Mr Trump’s lawyer Rudy Giuliani and Health and Human Services Secretary Alex Azar as being on the list. Mr Azar, who is of Lebanese descent, told the paper he was not interested, and Mr Giuliani could face confirmation hurdles. Deputy Secretary of State John Sullivan is another name on the list, according to Politico, and would have an easier confirmation process.

It is unlikely that a replacement will be confirmed before January, when the next Senate is installed with an additional two to three seats added to the Republicans' current majority. Mr Mueller, however, is expected to issue indictments before then.